This application relates to root canals. More particularly, this application relates to an improvement on the current material used for root canal obturation, the shaped gutta percha cone.
The purpose for filling the root canal is to seal in any remaining microorganisms so they do not come into contact with tissue, and to eliminate the possibility of bacterial attraction to the inflamed area. Complete obturation of the root canal is necessary to prohibit periapical exudate from draining into the canal, thereby either becoming an irritant itself or attracting bacterial contamination known as anachoresis.
The current method of obturating the root canal is by inserting a shaped cone of gutta percha, the material of choice since its introduction in 1867, into the prepared root canal. The basic formulation of gutta percha cones has not changed in over fifty years, except in the new milling process which changes the alpha form of gutta percha to the more easily moldable beta form. The general composition of the cone is: 20% gutta percha, a coagulated latex which is a trans isomer of rubber to serve as the matrix; 66% zinc oxide, as filler material; 10% barium or strontium, as the radiopacifier; 3% waxes or resins; 0.3% color pigments; small amounts of antioxidants and plasticizers. The above formula may vary slightly by manufacturer.
Gutta percha has been shown to be inert by numerous studies and is desirable because it does not shrink, is relatively non-irritating to tissue, non-staining, radiopaque, and can be molded to improve its adaptability. The newer version of this material is a highly milled form which allows improved physical adaptability.
Unfortunately, the newer beta form is more difficult to control and insert into the canal, and cannot easily be removed for retreatment of the root canal since it contains a metal core. Even the original alpha form of gutta percha is not always easily inserted into the root canal due to size restrictions or the curvatures of the canal. Although the current gutta percha cones are pliable, they do not fully conform to the anatomy of the root canal. Therefore, due to irregularities in the shapes of the canals, the gutta percha cones cannot always completely seal off the canal. They may not obturate the canal apically and they may not do so laterally. And if the canals are ovoid at the apex, the cones may not fully seal the apical foramen of the canal.
With the root canal only partially sealed, the chance of having difficulties with irritation of the affected area or bacterial contamination increases leading to infection and failure of the root canal. Even when the cone does seal the opening of the canal completely or almost completely, a gradual leaching out process from contact with tissue fluid will create more voids and poorer adaptation within the canal anatomy. The level of discomfort and pain associated with an irritated, inflamed, and/or infected root canal area can be great, followed by loss of the tooth. More importantly, with the present root canal filling material, these can be recurring problems leading to tooth extraction.
For the foregoing reasons, there is a need for a root canal filling material which is more pliable and gives additional protection against irritation and infection which current gutta percha cones do not provide. The antimicrobial gutta percha cone can fulfill this need.